1. Field of the Invention
The present invention relates to a holding cabinet, which provides a more consistent and accurate holding environment for food products. In particular, the invention relates to a holding cabinet, which provides a more consistent and accurate holding environment for food products by providing control of environmental conditions within the cabinet.
2. Description of Related Art
There is a demand for food holding devices that maintain food products at a substantially uniform temperature for selected periods of time while preserving the taste, moisture content, texture and quality of the food. Further, in other applications, it is desirable to be able to restore food products to acceptable quality after long storage periods.
Holding cabinets for cooked food products provide an environment in which certain environmental variables may be controlled to some degree. For example, air temperature may be controlled to a particular temperature level in an attempt to maintain the food product in a just-cooked state until it is served. These variables affect the quality of the food products. Several food product parameters are important to maintain food product quality. These product parameters include temperature, moisture content, color and texture. Texture is a complex combination of olfactory and gustatory sensations, which in turn are created by the mechanical and chemical properties of the food being held.
The initial food product parameters described above are primarily determined by the food product composition and the cooking process, but during holding, they are changed by the holding environment parameters. Exemplary environment parameters include air temperature, relative humidity, and airflow. Airflow can be considered as the mean speed at which air moves over the food product. Other environment parameters include heat conducted into the food product and radiant energy applied to the food product.
Previously, various methods and devices have been developed to attempt to maintain heat and humidity. These devices and methods, however, suffer from drawbacks such as high airflow and inaccurate temperature and humidity control. High airflow levels are detrimental to food quality over long periods. The airflow increases evaporative cooling from the food product, which causes the food product to cool excessively as well as reducing the moisture content below an acceptable level. Current holding cabinets may give acceptable results for short holding times, if the proper holding parameters are established and the cabinet can maintain the parameters within acceptable limits. Nevertheless, environmental parameters are not well controlled and holding times are limited before the quality of food products deteriorates below an acceptable level. More particularly, it has been found that air circulation characteristics and improper storage temperature contribute significantly to bacteria growth and excessive loss of moisture which leads to food shrinkage, so that in an improper storage atmosphere, the food deteriorates after only a short period of time and loses its tenderness, appetizing taste, and appearance. It has also been found that even where food is stored under favorable conditions in an enclosure, the food deteriorates at a rate dependent on the time the door to the enclosure is opened, exposing the storage chamber to the ambient atmosphere.
Additionally, it is known that in storage of some foods, such as fried chicken or fish, where a crust is provided, it is particularly desirable to maintain the crispness of the crust while minimizing the moisture loss from the underlying meat. Storage of such foods tends to involve the satisfaction of seemingly mutually exclusive conditions, to hold the crispness of the crust by maintaining low moisture content in the crust while minimizing moisture loss from the food. In such foods, excessive moisture-loss results in shrinkage and loss of tenderness and adversely affects the texture of the meat. This may be prevented by controlling the temperature and humidity of the storage atmosphere. The problem is preventing moisture flow from the underlying food to the crust while holding the crust in low moisture content.